A technique has been disclosed for providing an enhanced entertainment experience for players who participate in a game by allowing a plurality of players to simultaneously proceed with the conquest of a dungeon created by a dominant player and providing special benefits (authority to rebuild the dungeon) to a player who has successfully conquered the dungeon the fastest (see, for example, Japanese Unexamined Patent Application Publication No. 2009-112708).
The technique of the related art described above requires individual players to simultaneously participate in a game online, and a game in which a small number of players participate is low on entertainment. There is another problem in that a dominant player has no means for presenting a dungeon that the dominant player has created to other players and therefore interaction among the players is difficult to promote.